The present invention relates to body exercise equipment. More particularly, the present invention relates to exercise equipment such as that disclosed in the U.S. Pat. No. 6,705,976, the subject matter of which is incorporated herein by reference.
The human body moves primarily in circular or arcuate paths of motion, as evidenced by Leonardo Da Vinci's study of human proportions. From a biomedical standpoint, exercise equipment designed with resistance delivery systems oriented along an arced pathway are inherently more bio-mechanically optimized than those that are not. The aforesaid U.S. patent discloses two embodiments of exercise equipment of this type.
A first embodiment encloses a housing having a structural surface defining a prescribed concave arcuate contour having a number of cable exit points positioned along this surface. A number of cables, each having a proximal end and a distal end, are arranged such that the proximal end passes through one of the exit points and is attached to a gripping device, such as a handle, that enables the user to exert a tensile force in the cable by pulling the handle. The distal end of each cable is coupled to a common source of resistance such that, when the proximal end of each cable is pulled by a user, the source of resistance exerts a counterforce on the cable. Means are provided for retaining each cable in a retracted position when it is not being pulled by a user, even when one or more other cables is or are pulled by the user.
In a second embodiment, the exercise equipment comprises a frame having a track extending along a prescribed concave arcuate path. A moveable trolly, having an exit point for a cable, is repositionable to a number of fixed positions along the track. A single cable has a proximal end which extends through the exit point and is attached to a gripping device, such as a handle, that enables a user to exert a tensile force on the cable. The distal end of this cable is coupled to a source of resistance. Cable takeup means are provided, in the exercise equipment, for maintaining the length of the cable between its proximal end and the exit point through which it passes substantially constant, independent of the position of the trolley, and thus the exit point, along the track, when no tensile force is applied by the user.
While the exercise apparatus disclosed in the aforementioned U.S. Pat. No. 6,705,976 operates extremely well for the purpose for which it is intended, this and other exercise equipment of this type is relatively expensive to manufacture and to transport. One of the significant costs of this equipment involves the source of resistance applied to the cable or cables used in the machine. This source of resistance comprises, as a minimum, a plurality of weights which form a “weight stack” that is coupled to the distal end of the cable(s) and is lifted vertically when the proximal end of a cable is pulled by a user.
Weight stacks, which are normally guided by rods or rails to run vertically, include a device for selecting the number of weights in the stack that are to be lifted as a unit by the user. The weights that are not selected remain in the lower part of the stack while the selected weights are lifted upward.
With a mechanism of this type, it is difficult to obtain a “starting resistance” or minimum resistance of less than five pounds because, even if no weights are selected, the device for selecting the weights, itself, has a minimum weight. Particularly in the case of physical therapy applications, and for the severely de-conditioned or elderly persons, it is useful to be able to set the lowest resistance weight to zero, or near zero.
As noted above, a further disadvantage of this exercise equipment is that the weights incorporated into the weight stack present a significant cost to manufacture and transport. Also, the rods or rails, and the mechanism for selecting the weights to be lifted, add to the cost of the equipment. Furthermore, the cost of shipping the weights, rods, rails and mechanism for selecting the weights is not inconsiderable.